linux/drivers/mfd/tps6507x.c
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   1/*
   2 * tps6507x.c  --  TPS6507x chip family multi-function driver
   3 *
   4 *  Copyright (c) 2010 RidgeRun (todd.fischer@ridgerun.com)
   5 *
   6 * Author: Todd Fischer
   7 *         todd.fischer@ridgerun.com
   8 *
   9 * Credits:
  10 *
  11 *    Using code from wm831x-*.c, wm8400-core, Wolfson Microelectronics PLC.
  12 *
  13 * For licencing details see kernel-base/COPYING
  14 *
  15 */
  16
  17#include <linux/module.h>
  18#include <linux/moduleparam.h>
  19#include <linux/init.h>
  20#include <linux/slab.h>
  21#include <linux/i2c.h>
  22#include <linux/mfd/core.h>
  23#include <linux/mfd/tps6507x.h>
  24
  25static struct mfd_cell tps6507x_devs[] = {
  26        {
  27                .name = "tps6507x-pmic",
  28        },
  29        {
  30                .name = "tps6507x-ts",
  31        },
  32};
  33
  34
  35static int tps6507x_i2c_read_device(struct tps6507x_dev *tps6507x, char reg,
  36                                  int bytes, void *dest)
  37{
  38        struct i2c_client *i2c = tps6507x->i2c_client;
  39        struct i2c_msg xfer[2];
  40        int ret;
  41
  42        /* Write register */
  43        xfer[0].addr = i2c->addr;
  44        xfer[0].flags = 0;
  45        xfer[0].len = 1;
  46        xfer[0].buf = &reg;
  47
  48        /* Read data */
  49        xfer[1].addr = i2c->addr;
  50        xfer[1].flags = I2C_M_RD;
  51        xfer[1].len = bytes;
  52        xfer[1].buf = dest;
  53
  54        ret = i2c_transfer(i2c->adapter, xfer, 2);
  55        if (ret == 2)
  56                ret = 0;
  57        else if (ret >= 0)
  58                ret = -EIO;
  59
  60        return ret;
  61}
  62
  63static int tps6507x_i2c_write_device(struct tps6507x_dev *tps6507x, char reg,
  64                                   int bytes, void *src)
  65{
  66        struct i2c_client *i2c = tps6507x->i2c_client;
  67        /* we add 1 byte for device register */
  68        u8 msg[TPS6507X_MAX_REGISTER + 1];
  69        int ret;
  70
  71        if (bytes > TPS6507X_MAX_REGISTER)
  72                return -EINVAL;
  73
  74        msg[0] = reg;
  75        memcpy(&msg[1], src, bytes);
  76
  77        ret = i2c_master_send(i2c, msg, bytes + 1);
  78        if (ret < 0)
  79                return ret;
  80        if (ret != bytes + 1)
  81                return -EIO;
  82        return 0;
  83}
  84
  85static int tps6507x_i2c_probe(struct i2c_client *i2c,
  86                            const struct i2c_device_id *id)
  87{
  88        struct tps6507x_dev *tps6507x;
  89
  90        tps6507x = devm_kzalloc(&i2c->dev, sizeof(struct tps6507x_dev),
  91                                GFP_KERNEL);
  92        if (tps6507x == NULL)
  93                return -ENOMEM;
  94
  95        i2c_set_clientdata(i2c, tps6507x);
  96        tps6507x->dev = &i2c->dev;
  97        tps6507x->i2c_client = i2c;
  98        tps6507x->read_dev = tps6507x_i2c_read_device;
  99        tps6507x->write_dev = tps6507x_i2c_write_device;
 100
 101        return mfd_add_devices(tps6507x->dev, -1, tps6507x_devs,
 102                               ARRAY_SIZE(tps6507x_devs), NULL, 0, NULL);
 103}
 104
 105static int tps6507x_i2c_remove(struct i2c_client *i2c)
 106{
 107        struct tps6507x_dev *tps6507x = i2c_get_clientdata(i2c);
 108
 109        mfd_remove_devices(tps6507x->dev);
 110        return 0;
 111}
 112
 113static const struct i2c_device_id tps6507x_i2c_id[] = {
 114       { "tps6507x", 0 },
 115       { }
 116};
 117MODULE_DEVICE_TABLE(i2c, tps6507x_i2c_id);
 118
 119
 120static struct i2c_driver tps6507x_i2c_driver = {
 121        .driver = {
 122                   .name = "tps6507x",
 123                   .owner = THIS_MODULE,
 124        },
 125        .probe = tps6507x_i2c_probe,
 126        .remove = tps6507x_i2c_remove,
 127        .id_table = tps6507x_i2c_id,
 128};
 129
 130static int __init tps6507x_i2c_init(void)
 131{
 132        return i2c_add_driver(&tps6507x_i2c_driver);
 133}
 134/* init early so consumer devices can complete system boot */
 135subsys_initcall(tps6507x_i2c_init);
 136
 137static void __exit tps6507x_i2c_exit(void)
 138{
 139        i2c_del_driver(&tps6507x_i2c_driver);
 140}
 141module_exit(tps6507x_i2c_exit);
 142
 143MODULE_DESCRIPTION("TPS6507x chip family multi-function driver");
 144MODULE_LICENSE("GPL");
 145
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